Pin lock



March 9, 1943. F. M. BLANCHARD 2,313,216

' v PIN Loox 'med Dec. 12, 1941 2 sheets-sheet 1 March 9, 1943. F. M. BLANCHARD 2,313,216

i PIN LOCK Filed Dec. 12, 1941 2 sheets-sheet 2 IIIIIIIIIIIIIIII INVENTOR Patented Mar. 9, 1943 PIN LOOK Floyd Martin vlanchard, San Francisco, Calif., assigner to Yuba Manufacturing Company, San Francisco, Calif., a corporation of California Application December 12, 1941, Serial No. 422,667

1 Claim'.

My invention relates to means for securing the pivot pins in endless chains such as chains of dredge buckets and is particularly concerned with that type of machinery, although applicable elsewhere. The structure is somewhat akin to that disclosed in my prior Patent 2,134,222, issued October 25, 1938, wherein is found a general statement of the eld of usefulness of structures of the current character.

It is an object of my present invention to provide a positive p'in lock which is useful in- 'connection with headless bucket pins.

Another object of my invention is to provide an improved manner of retaining a headless bucket pin against rotary and axial movement.

An additional object oi my invention is to provide a pin lock which can be adapted to dredge buckets originally manufactured for u'se with pins having the customary L head.

An additional object of my invention is to provide a pin lock which is effective not only to restrain rotary motion of the pin, but likewise to restrain longitudinal axial motion thereof in order to eliminate consequent wear between adjacent parts.

The foregoing and other objects are attained in the embodiments of the invention illustrated in the drawings, in which- Fig. 1 is a side elevation of one form of pin lock constructed in accordance with my invention.

Fig. 2 is a cross-section the plane of which is indicated by the line 2-2 of Fig. 1.

Fig. 3 is a detailed cross-section the plane of which is indicated by the line 3-3 of'Fig. 1.

Fig. 4 is a side elevation of another form of pin lock construction in accordance with my invention.

Fig. 5 is a cross-section the plane of which is indicated by the line 5 5 of Fig. 4. v

Fig. 6 is a cross-section the plane of which is indicated by the line 5&5 of Fig. 4. I

Fig. 7 is a cross-section similar to Figi. 6 but showing a modied form of retaining means.

In its preferred form the pin lock of my invention is adapted for use with a dredge bucket having a transverse circular eye and an adjacent abutment wall or walls. Within the eye is situated a circular bucket pin having at the end one or more flat faces forming a chord or a portion of an inscribed polygon within the circumference of the pin and located between the center of the pin and the abutment wall. Cooperating with the face or faces is a block designed to abut the end portion of the bucket pin and SGL the abutment wall, being positively forced and locked into such location by' a screw means. Preferably, the block is restrained against movement with respect to the bucket body and consequently similarly restrains the bucket pin against axial and rotary movement.

In the rst form of my invention.' as disclosed in Figs. 1 to 3 inclusive, there ls provided the customary dredge bucket body 5, which is not illustrated in detail since its Iconstruction is well known. 'Such bucket body, however, includes a portion 6 containing a circular-cylindrical bore 'l constituting an eye. Customarily, a pair of such spaced eyes is provided on the front of each bucket body to straddle a central back eye 8 on the succeeding bucket body with all of the eyes in alignment transversely of the direction of motion of the bucket line.

Adapted to be disposed within the aligned eyes is a bucket pin 9. This preferably is a round or circular-cylindrical metal member which is designed to be anchored in one of the buckets and to pivot in the other. Inthe present instance, the pin 9 is anchored within the front spaced eyes l so that the back eye 8 of the adjacent bucket can rotate thereon. It is also desirable that the bucket pin be reversible from end to end and also to be rotated through substantially a half circle or less during some period of its life 'in order that Wear can be distributed as widely as possible over the full circumference of the pin. For this reason the pin 9 is made symmetrical on opposite sides of its center, that is, lit is the same at b-oth ends, and hence a description of :but one end applies to both ends.

Adjacent one end, for example, the pin 9 is reduced in size or is machined or burned to provide a face II which is a planar face parallel to the central axis I2 of the pin and in effect is in end elevation substantially a chord of the circular circumference of the pin. Preferably, the face I I is duplicated by the provision of an additional face I3 of a similar character and so disposed that the faces coincide approximately with the zone I 4 of maximum wear on the pin. As illustrated in Fig. 1, a back eye bushing I6 which bears on the pin oscillates between the two dotted line positions A and B so that the maximum wear is substantially intermediate the two extremes shown. Consequently. I preferably arrange it so that the faces il and I 3 are approximately' symmetrical with respect to the zone of maximum wear and are disposed on one side of the center or axis I2'. Vn order that the pin may be rotated a half turn or less to distribute wear, or turned end for end and also rotated, I provide within the circular diameter of the pin additional, duplicate faces I1 and I8 so that when the pin is rotated approximately 180 degrecs the faces I1 and I8 will bear the same relationship to the zone 4 of maximum wear as do the faces I| and I3 initially.

The arrangement of the faces is such as to provide in end elevation substantially a polygon inscribed within the circumference of the pin and the polygon can be considered to be made up of any number of faces more than one. While four faces are shown, in the present instance, it is feasible to utilize two faces or any additional number, although some multiple of two is preferred since the zone I4 of wear usually extends for approximately one-half of the circumference.

To cooperate with the pin 9 I preferably provide a slideable block 2| which has one or more faces 22 and 23 arranged in a polygonal form similar to the shape of the pin end so as to match `or meet the currently cooperating faces and I3, for example. The block 2| preferably has planar side faces to abut the similar abutment walls of the dredge bucket. These faces can be parallel to c-ooperate with similar parallel walls on buckets designed for L headed pins, butin the present instance I have shown a further refinement. The dredge bucket is provided with abutment walls 26 and 21 which have planar faces 28 and 29 thereon converging toward the axis I2. Also formed upon the dredge bucket is a surfaced boss 3l cooperating with the faces 28 and 29 to define a slide channel for the block 2|. The faces 28 and 29 run out into or merge with an enlarged recess 33 partially defined by the extended portions of the abutment walls 26 and 21 and partially defined by a cross-wall 34 forming part of the dredge bucket body. The block 2| has inclined faces- 36 and 31 thereon designed to run upon the faces 28 and 29 and also has contact with the boss 3| to preclude endwise or axial movement of the block.

Movement of the block 2| in a direction perpendicular to the axis I2 is regulated by a screw mechanism such as a threaded central stem 38 designed to pass through an aperture 39 in the fixed end wall 34. A pair of nuts 4| and 42 are disposed on the stem 38 on opposite sides 'of the wall 34 and upon suitable manipulation of the nuts, the block 2| is appropriately positioned and is forced and locked into close positive abutment with the end of the pin 9 and is wedged into tight relationship with the faces 28 and 29. Any rotational tendency in either direction of the pin 9 acts through the wedgelike portions 22 and 23 of the block 2| to transfer the forces to the dredge bucket body and to preclude turning movement of the pin.

Since the block 2| is constrained against axial movement by tapered sides 36 and 31 and by the boss 3|, and since it abuts shoulders 43 onthe pin left when the faces I and I3, for example, are cut, and since such blocks are provided at opposite ends of the pin, the pin itself is positively precluded from any axial movement. This is particularly important as any axial movement of the pin beyond the side of the bucket will cause serious interference with adjacent moving parts. After the pin has worn somewhat between the eyes 1, thereby forming a shoulder at each end of zone I 4, the interposed back bucket eye 8 on the adjacent bucket is displaced longitudinally by the tension in the bucket line and thus itself precludes any axial movement so that the described end restraint by the blocks is important to prevent initial axial motion.

In order to assemble the block with the pin the aperture 39 is preferably relieved at diagonally opposite corners to provide a transversely elongated bore 44 so that, as shown in dotted lines in Fig. 2, the stem 38 can be diagonally inserted through the aperture 39 and then slightly rotated as the block 2| is positioned within the recess 33. Subsequently, by operation of the nut 4|, for example, the block is advanced to contact the end of the pin and hold it positively in position.

The aperture 39 can be replaced with a slot opening outwardly through the end wall 34. In that case it is not then necessary to have such a long stem 3B on the block 2| and the shorter stem is suiiciently stiff and rigid when the nuts 4| and 42 are clamped tightly to hold the block against the shoulders 43 on the pin against any initial axial motion. When the pin wears somewhat so that it can no longer have any axial motion, the short stiff stem 38 is relieved of the force. Tapered faces 36 and 31 on the block 2| may be used or may be replaced by parallel sides.

With this form of the invention the pin can be turned end for end and can be rotated periodically in order to distribute wear in the most advantageous manner. The construction can be employed in newly designed dredge buckets or it can well be adapted to dredge buckets now in service simply by welding or otherwise fastening in the end wall 34, the walls 26 and 21 being normally in place to cooperate with the sides of a locking block.

In a modified form of my invention shown in Figs. 4, 5 and 6, the general arrangement is approximately the same in that the dredge bucket body 56 is provided adjacent the eye 51 with substantially parallel abutment walls 58 and 59. Disposed Within the eye 51 is a circularcylindrical bucket pin 6| which is symmetrical on opposite ends and is cut away or reduced on chords of the circumference to provide faces 62 and 63 on opposite sides of the center or axis 64. These faces are preferably parallel with the axis of the pin. The number of faces can be varied, but in view of the nature of the wear, it is preferred that a multiple of two be afforded and that they be positioned as indicated in connection with the arrangement of Figs. 1 to 3.

Adapted to cooperate with the adjacent one of the faces 62 or 63, is a block 66 in this instance in the form of a wedge when viewed in side elevation, that is, being wider at the bottom than at the top. When viewed in plan, the sides of the block are substantially parallel, although they can also be slightly arcuate or rounded. The block is designed not only to abut the pin 6| but is likewise designed to abut a portion of an end wall 61 spanning the space between the abutment walls 58 and 59. The end wall 61 has an outstanding surfaced boss 68 which is appro-l priately inclined to cooperate with the meeting face on the block 66. The block is provided with a central aperture 69 through which and through R an aligned aperture 1| in the wall 58 ispassed a tightening device such as a bolt 12 and a nut 13. As shown in Fig. 7, the nut and bolt may be replaced with a stud 14 and cooperating threads in block 66.

In originally assembling the device, the pin 6I is put in position, the Wedge block 56 is put in its lowermost position and is then pulled or moved upwardly by the installation and operation of the bolt 'I0 and nut 'Il (or the stud 14) until all of the parts are in tight Iengagement. Any tendency toward rotation in either direction of the pin 6| is transferred to the Wedge block 56 and by it conducted to the end Wall 61 and through the fastening devices 'l0 and 'H (or 14) to the main bucket body. In this fashion the pin 6l is positively precluded from rotation. Furthermore, because of the well supported bolt 'l2 (or stud 14) no bending in the fastening means will occur. Thus, the pin is precluded from any axial motion and is retained accurately positioned until it is worn suliciently to remain centralized. After a period of some Wear the block 66 can be completely loosened and removed, the pin Bl rotated through a half turn or Whatever is the appropriate amount to bring the next faces into position and the Wedge block 66 is repositioned and tightened. Alternatively, the pin 6I can be turned end for end in order further to distribute the Wear.

In this form of device, a standard dredge bucket body can be utilized insofar as the abutment Walls 58 and 59 are concerned, it is merely necessary to Weld or otherwise fasten in an end Wall 61 of an appropriate shape. The same general advantages of the distribution of Wear, adap-` tation to old and new design, and positive locking are aiorded in both forms of the invention disclosed herein.

Both forms of locking device provide a positive take up of any longitudinal elongation in bucket eyes l and 5l, and also any wear caused by vibration of pin in these eyes. Dredge buckets are commonly made of cast manganese steel which when subject to heavy stress, as applied to buckets, will stretch and unless the pin is securely locked in place Wear is increased by movement of pin in this enlarged pin hole.

The locking device is preferably placed on both ends of the pin as it has been found that the torsional stress to which the pin is subjected is suicient to cause rotary movement and consequent Wear if one end of the pin only is locked in place.

I claim:

A pin lock for a dredge bucket having a transverse circular eye and an abutment Wall comprising a pin disposed within said eye and having a chordal end portion, a threaded stem member engaging said bucket and having a central axis, and a block coacting with said stem member and having faces thereon symmetrical about said axis and adapted to abut cooperating symmetrical faces on said end portion and on said bucket.

FLOYD MARTIN BLANCHARD. 

